Extinct in the wild since the 1970s, the rare Przewalski horse is making a comeback: not only have several foals been born in zoos this year, but a program to reintroduce the breed back into their native Mongolian habitat is showing success.

The Przewalksi’s horse, pronounced pshuh-vahl-skeez (to hear the pronunciation, use this audio link from dictionary.com) is the last truly “wild” horse. Unlike mustangs, the Przewalksi’s horse actually is genetically different to domestic horses, having 66 chromosomes rather than 64. Like the zebra, the Przewalksi’s horse has never been domesticated; even those that live in zoos are not ridable.

The Przewalksi’s horse is a native of Mongolia. Although the breed is the last link to ancient horses, it has a relatively modern name. It was “discovered” in the late 19th century after Polish naturalist Colonel Nikolai Przewalski and named after him.

The Przewalski horse is small but stocky, standing between 12 and 14 hands.

Przewalski horses are always dun with a lighter color around the muzzle, an “eel-stripe” or black dorsal stripe, and zebra striping on the legs. It has an upright mane and no forelock, and a tail that is more reminiscent of a donkey than a domestic horse.

Today’s population of approximately 3,000 Przewalksi’s horses are descended from a group of foals that was captured during an expedition in the early 20th century. Only 53 foals survived the journey from Mongolia to Europe. Of this group, only 13 of them reproduced. It is pretty amazing to think that what remains of this breed comes from such a small genetic foundation.

The problem was that the Przewalksi’s horse is difficult to breed in captivity. Originally there was very little exchange among zoos, which resulted in inbreeding and, ultimately, genetic problems that increased foal mortality and shortened lifespan. By 1977, there were only 300 surviving Przewalksi’s horses in the world.

At this time, a small group of Dutch citizens formed The Foundation for the Preservation and Protection of the Przewalski Horse. It established a computerized studbook and began encouraging and supporting the exchange of Przewalski horses between zoos in an effort to diversify the breed as much as possible.

Its ultimate goal was the reintroduction of Przewalski horses into the wild, a process that began in

1981 when the foundation purchased horses from zoos and began teaching them how to forage in the wild and live in herds. Within the program of the Foundation, breeding success went up and foal mortality dropped. In 1990, the Przewalksi’s horse reintroduction program began, releasing the horses into a 24,000 acre steppe area in Mongolia.

So far, the program has been a success and the Przewalski’s horse is thriving back in the wild.